This relates generally to electronic devices, and more particularly, to electronic devices with displays.
Electronic devices often include displays. For example, cellular telephones and computers may have displays for presenting information to a user.
Liquid crystal displays contain a layer of liquid crystal material. Pixels in a liquid crystal display contain thin-film transistors and electrodes for applying electric fields to the liquid crystal material. The strength of the electric field in a pixel controls the polarization state of the liquid crystal material and thereby adjusts the brightness of the pixel.
Substrate layers such as color filter layers and thin-film transistor layers are used in liquid crystal displays. A thin-film transistor layer contains an array of thin-film transistors and associated pixel electrodes that are used in controlling electric fields in the liquid crystal layer. A color filter layer contains an array of color filter elements such as red, blue, and green elements. The color filter layer provides the display with the ability to display color images.
The color filter layer contains a black masking material that is patterned to form a grid-shaped black matrix. Openings in the black matrix contain color filter elements. Conventional black matrix openings have gently sloped sidewalls, which can give rise to undesired color mixing between adjacent pixels, particularly in high resolution displays in which small amounts of misalignment between the color filter layer and thin-film transistor layer can be difficult to completely eliminate.
It would therefore be desirable to provide displays with reduced color mixing.